Plex remote access not working

Apps and Virtualization
,
1

Just moved from TrueNAS CORE 3.3 to Scale 25.04.0 and installed Plex.
Remote access is not working and the server is not found if I start my iPad app.

Unlike the 3.3 CORE, the user interface seems to be on the same IP address
as TrueNAS, but at port 32400. I.E: X.X.X.X. My router has external IP address Y.Y.Y.Y.

If I open http://X.X.X.X:32400/web/index.html, I get access to the server.

I named the Plex server on Scale the same as the Plex server on CORE,
but I removed the CORE server afterwards.

The Plex Media Server reports that remote access is not available.

Private 172.16.1.2 : 32400 ← Public Y.Y.Y.Y : 0 X Internet

Why not
Private X.X.X.X : 32400 ← Public Y.Y.Y.Y : 32400 Internet?

The “172.16.1.2” is not the address of the Plex Server and not accessable from my network. Why is it not using the correct address?
I can see from the settings->network that this is the address of eth0.

2

Switching my router DNS from the local provider to Google (8.8.8.8) seems to have fixed the problem.

3

Yeah, Plex does some funky things with DNS to let you use a valid TLS certificate for your server (which it obtains automatically). But I’ve found this test to give false negatives pretty consistently–it will say “remote access not available,” but I’ll be able to access remotely without a problem. And that’s not even accounting for things like Tailscale, which make remote access easier than it’s ever been.

4

Before I switched DNS to 8.8.8.8 I could not even have access on the local network using the app, since the server was not found on plex.tv.